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<BODY><H2><a href="../contents.htm">Tcl8.6.11/Tk8.6.11 Documentation</a> <small>&gt;</small> <a href="contents.htm">Tcl C API</a> <small>&gt;</small> Concat</H2>
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<H3><A NAME="M2">NAME</A></H3>
Tcl_Concat &mdash; concatenate a collection of strings
<H3><A NAME="M3">SYNOPSIS</A></H3>
<B>#include &lt;tcl.h&gt;</B><BR>
const char *<BR>
<B>Tcl_Concat</B>(<I>argc, argv</I>)<BR>
<H3><A NAME="M4">ARGUMENTS</A></H3>
<DL class="arguments">
<DT>int <B><A HREF="../TclCmd/tclvars.htm">argc</A></B> (in)<DD>
Number of strings.
<P><DT>const char *const <B>argv[]</B> (in)<DD>
Array of strings to concatenate.  Must have <I>argc</I> entries.
<P></DL>
<H3><A NAME="M5">DESCRIPTION</A></H3>
<B>Tcl_Concat</B> is a utility procedure used by several of the
Tcl commands.  Given a collection of strings, it concatenates
them together into a single string, with the original strings
separated by spaces.  This procedure behaves differently than
<B><A HREF="../TclLib/SplitList.htm">Tcl_Merge</A></B>, in that the arguments are simply concatenated:
no effort is made to ensure proper list structure.
However, in most common usage the arguments will all be proper
lists themselves;  if this is true, then the result will also have
proper list structure.
<P>
<B>Tcl_Concat</B> eliminates leading and trailing white space as it
copies strings from <B><A HREF="../TclCmd/tclvars.htm">argv</A></B> to the result.  If an element of
<B><A HREF="../TclCmd/tclvars.htm">argv</A></B> consists of nothing but white space, then that string
is ignored entirely.  This white-space removal was added to make
the output of the <B><A HREF="../TclCmd/concat.htm">concat</A></B> command cleaner-looking.
<P>
The result string is dynamically allocated
using <B><A HREF="../TclLib/Alloc.htm">Tcl_Alloc</A></B>;  the caller must eventually release the space
by calling <B><A HREF="../TclLib/Alloc.htm">Tcl_Free</A></B>.
<H3><A NAME="M6">SEE ALSO</A></H3>
<B><A HREF="../TclLib/StringObj.htm">Tcl_ConcatObj</A></B>
<H3><A NAME="M7">KEYWORDS</A></H3>
<A href="../Keywords/C.htm#concatenate">concatenate</A>, <A href="../Keywords/S.htm#strings">strings</A>
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